Surface Water Quality

The Texas Surface Water Quality Standards establish explicit goals for the quality of streams, rivers, lakes, and bays throughout the state. The Standards are developed to maintain the quality of surface waters in Texas so that it supports public health and enjoyment and protects aquatic life, consistent with the sustainable economic development of the state.

Texas Surface Water Quality Standards

Water quality standards identify appropriate uses for the state’s surface waters, including aquatic life, recreation, and sources of public water supply (or drinking water). The criteria for evaluating support of those uses include dissolved oxygen, temperature, pH, dissolved minerals, toxic substances, and bacteria. Statewide standards may be revised on a site-specific basis when sufficient information is available. The Texas Surface Water Quality Standards are codified in Title 30, Chapter 307 of the Texas Administrative Code.

Classifications of Surface Water

The major surface waters of the state are classified as segments for purposes of water quality management and for the designation of site-specific uses and criteria. Management includes activities such as assessment of in-stream water quality, issuance of permits to discharge into state waters, or allocation of grant funds. Classification supports the operation of the state’s programs to assure compliance with state and federal requirements. Basins Classified segments are aggregated by basin.
The basins are categorized as follows:

• River Basin Waters Surface inland waters comprising the major rivers and their tributaries, including listed impounded waters and the tidal portion of rivers to the extent that they are confined in channels.
• Coastal Basin Waters Surface inland waters, including listed impounded waters (but exclusive of River Basin Waters) that discharge, flow into, or otherwise communicate with bays or the Gulf of Mexico. Coastal Basin Waters include the tidal portions of streams to the extent that they are confined in channels.
• Bay (Estuary) Waters All tidal waters, exclusive of those included in river basin waters, coastal basin waters, and gulf waters. Most coastal waters in Texas are named as bays, but have freshwater inflows that make them estuaries. Variation in the salinity regimes is one of the unique features of these waters.
• Gulf Waters that are not included in or do not form a part of any bay or estuary but which are a part of the open waters of the Gulf of Mexico within the limit of the state’s jurisdiction.